The following description relates to a device for loading a container having contents therein, melting the contents and delivering the melted contents, i.e., a fluid, to a device for applying the fluid onto an article.
A traditional hot melt system includes a melting unit for melting a hot melt adhesive and an application device for applying the adhesive on an article. Generally, the melting unit is fluidically coupled to the application device and delivers the melted adhesive to the application device.
The melting unit is configured to receive a supply of hot melt adhesive initially in a solid form. The solid hot melt adhesive is typically stored in a container, such as a 55 gallon drum, that is loaded into the melting unit. To load the melting unit, the drum is typically positioned on a platform or other surface within a support structure of the melting unit. An upper end of the drum is open, exposing the hot melt adhesive.
The melting unit may include a drive mechanism configured to drive a heated member into hot melt adhesive through the open end of the drum. The drive mechanism is typically a piston system that may be, for example, hydraulically powered. The heated member is typically a plunger in the form of, for example, a platen or cylinder that is driven into, or into contact with, the hot melt adhesive by the piston assembly. The heated member contacts the adhesive and causes the adhesive to melt. The melted adhesive may be drawn away from the drum for use with an application device.
To replace an empty drum, the melting unit is stopped, i.e., the piston is withdrawn from the drum, the drum is removed, and then replaced with a full hot melt adhesive drum. During this time, the application device may be stopped as well. Thus, a situation may arise where the melted adhesive may not be applied to an article while the drum of hot melt adhesive is being replaced. That is, replacing a drum of hot melt adhesive in the melting unit may disrupt the flow of melted adhesive to the application device, thereby disrupting the application of adhesive to an article. Accordingly, it may be required to shutdown or idle the system to replace the hot melt adhesive drum. As a result, manufacturing time may be increased due to non-continuous operation of the melting unit and application device.
Some hot melt systems may include two or more individual melting units. Thus, when a drum in one melting unit is emptied, hot melt adhesive may be melted and drawn from another adhesive drum in another melting unit. In this configuration, an empty drum may be replaced while adhesive is drawn from another drum and supplied to the application device. Accordingly, a steady supply of melted adhesive may be supplied to the application device.
However, this configuration requires excess components and increases complexity. For example, as described above, this configuration uses two or more melting units instead of one, and requires the implementation of additional pumps and other associated equipment for delivery of the melted adhesive to the application device.
Smaller scale melting units are known, where a hopper may define a receptacle having heated surfaces therein. A supply of hot melt adhesive may be added to the hopper as necessary, melted, and discharged. However, with this device the hopper is not suited to receive a 55 gallon drum of hot melt adhesive. Rather, the hopper is sized to accept smaller amounts of hot melt adhesive, for example, as shavings or pellets. Thus, extra processing of the hot melt adhesive slug is required to provide a supply suitable for use with this type of device. Moreover, due the limited size of the device, the hopper may need to be frequently refilled, increasing labor costs.
Further, in a facility where the hot melt system is installed, vehicles, cranes, people or other moving devices or equipment may pass by the hot melt system in close proximity thereto. The possibility exists that the moving devices or objects may inadvertently come into contact with external or exposed portions of the hot melt system or the drum, potentially damaging the drum or external portions of the hot melt device. Further, the hot melt adhesive, as it is melted in the drum, may be exposed to surrounding environs, and in some cases, may bubble or splatter and come into contact with objects in close proximity thereto.
Accordingly, it is desirable to provide a fluid delivery device that may provide a continuous output of fluid and provide an enclosed area for transport and/or melting of the adhesive. In addition, it is desirable to provide a fluid delivery device where delivery of the fluid from the device may be individually, independently metered to different metering or application devices.